DE102009047487A1 - light module - Google Patents

Abstract

The light module (1) has a printed circuit board (2) which is equipped at its front with at least one light source (3), in particular light emitting diode, and further a hollow light guide (4), which laterally revolving around the at least one light source (3) surrounds and extends beyond the at least one light source (3) to the front, wherein an inner side (4a) of the light guide (4) is at least partially reflective and a front opening of the light guide (4) a light exit opening (L) of the light module (1 ) corresponds.

Description

The invention relates to a lighting module, comprising a printed circuit board, which is equipped on its front side with at least one light source, in particular light emitting diode.

Compact light modules based on light-emitting diodes require boards on which both the light-emitting diodes themselves (eg individual light-emitting diodes) and electronic components for the operation and regulation of the light-emitting diodes and thus the light emission are mounted. Downstream optics (eg lenses or reflectors) must be positioned at a disadvantageous distance from the actual light-emitting diodes due to typically larger component heights and electrical distances to be maintained, which leads to poor coupling efficiency into the optics.

DE 10 2007 015 475 A1 discloses a multiple light emitting diode module having a plurality of light emitting diodes with at least first and second light emitting diodes and a light mixing element having a cavity and / or a light mixing rod, wherein the light mixing element has a reflective surface and a light exit surface of the plurality of light emitting diodes in operation emitted electromagnetic radiation is reflected at the reflective surface and thereby mixed and the reflected and mixed radiation is coupled out through the light exit surface. This multiple light-emitting diode module has the disadvantage that complex and costly and difficult to cool constructions are required with multiple interconnected boards.

It is the object of the present invention to at least partially avoid the disadvantages of the prior art and, in particular, to provide a simply constructed, easily and effectively optically contactable lighting module.

This object is achieved according to the features of the independent claims. Preferred embodiments are in particular the dependent claims.

The object is achieved by a lighting module, which has a printed circuit board, which is equipped on its front side with at least one light source, and a hollow light-guiding element, which surrounds the at least one light source laterally encircling and extends beyond the at least one light source to the front, wherein an inner side of the light-guiding element is at least partially reflective and a front-side opening of the light-guiding element corresponds to a light exit opening of the light-emitting module.

The light of the light source (s) is guided from the plane of the light source (s) to a higher level of the light module, namely to the plane of the light exit opening, by means of the light guide element, which acts as a "light channel". As a result, a space required for electronic components (capacitors, resistors, driver components, etc.) can be bridged and a new, higher light output level can be defined. Attachment elements (optical or optically active elements, etc.) can then be brought as close as possible to the light exit opening as the new light-emitting plane, whereby Einkoppelverluste be avoided.

The fact that the light-guiding element surrounds the at least one light source laterally also encompasses the case in which the light-guiding element is offset in front relative to the light source, ie can have a (mostly small) vertical distance to the at least one light source (more precisely, its emitter surface). However, it is preferred to avoid light loss if the light guide is not offset from the light source to the front.

Preferably, the at least one light source comprises at least one light-emitting diode. If several LEDs are present, they can be lit in the same color or in different colors. A color can be monochrome (eg red, green, blue, etc.) or multichrome (eg, white). The light emitted by the at least one light-emitting diode can also be an infrared light (IR LED) or an ultraviolet light (UV LED). Several light emitting diodes can produce a mixed light; z. B. a white mixed light. The at least one light-emitting diode may contain at least one wavelength-converting phosphor (conversion LED). The at least one light-emitting diode can be in the form of at least one individually housed light-emitting diode or in the form of at least one LED chip. Several LED chips can be mounted on a common substrate ("submount"). The at least one light emitting diode may be equipped with at least one own and / or common optics for beam guidance, z. At least one Fresnel lens, collimator, and so on. Instead of or in addition to inorganic light emitting diodes, z. Based on InGaN or AlInGaP, organic LEDs (OLEDs, eg polymer OLEDs) can generally also be used. Also z. B. diode lasers are used. Alternatively, the at least one light source z. B. have at least one diode laser.

It is an embodiment that a plane of the light exit opening is parallel to a plane of the at least one light source. As a result, the "light interface" can be simply moved forward from the plane of the light source (s) in which it is located in the direction of the main emission direction be raised optical axis. Alternatively, the plane of the light exit opening can be arranged at an angle to the plane of the at least one light source.

It is still an embodiment that the light guide element has a substantially hollow cylindrical basic shape. This form is particularly easy to produce and assemble.

It is also an embodiment that the light guide element consists of an electrically non-conductive or dielectric material. Thus, electrically conductive attachment elements (eg aluminum reflectors) can be isolated from the electrically conductive parts on the printed circuit board, which simplifies compliance with creepage distances and creepage distances. The light guide may for example consist of a plastic, z. PC, PMMA, COC, COP, or glass.

It is also an embodiment that the lighting module has at least one receiving means for receiving an attachment element via the light exit opening. This receiving means can be used in particular for a positional adjustment of the attachment element with respect to the light exit opening. In particular, the receiving means can have a ('standardized') position relative to the light exit opening that is also defined for different lighting modules so as to be able to design a design of attachment elements substantially independently of a design of such lighting modules (without the attachment element).

It is a particular embodiment that the receiving means is designed as a mounting interface to be able to fasten the attachment element with a suitable configuration with a defined position with respect to the light exit opening on the light module. The attachment interface may be, for example, a part of a bayonet closure, a screw cap (generally a twist lock), a buckle, etc.

It is yet an embodiment that the light module has a cover for at least a part of arranged on the front side of the printed circuit board electronic components, wherein a front side of the cover is located substantially in the plane of the light exit opening. As a result, in particular a substantially planar front surface of the lighting module can be achieved, in which the light exit opening is substantially flush-mounted.

It is yet another embodiment that the light guide is laterally surrounded at least partially circumferentially by a ring cover for at least a portion of arranged on the front side of the circuit board electronic components. Thus, the, in particular central, z. B. circular, area for the at least one light source of a surrounding this, in particular ring-shaped, area to be separated in a particularly compact and easy to install spatially.

It is a development that the light guide element by the light exit opening provides direct access to the at least one light source, ie z. B. has no cover. Thus, a loss of light between the at least one light source and the light exit opening can be minimized.

It is still a further development that the light-guiding element has a forwardly widening (reflecting) inside. The inside can z. B. have a substantially frusto-conical contour. This provides the advantage that the radiation of the light beam emitted by the at least one light source can be collimated, resulting in a narrower angular distribution. It has proven to be advantageous that an angle bevel (also called "draft angle") α lies in a range between 1 ° and 10 °, in particular between 1 ° and 5 ° (including the end values).

It is an alternative embodiment that the light guide has a forwardly tapered inside, z. B. with an inverted frusto-conical contour. This results in the advantage that an emission of the light beam emitted by the at least one light source can be decollimated, which results in a narrower angular distribution. It has proved to be advantageous that the angle bevel α lies in a range between -1 ° and -10 °, in particular between -1 ° and -5 ° (including the end values).

It is still an embodiment that the inside of the light-guiding element has an optically effective surface structure. Thus, in particular a light mixture, for. In relation to a brightness and / or a color of the light emitted by the at least one light source, in a simple and compact manner.

It is a development that the surface structure comprises a wave structure or is formed by means of such. The wave structure may, for. B. comprise a sinusoidal wave structure, but also a shape based on splines or even a free form. It has proved to be advantageous that a so-called "peak-to-valley" angle β of the wave structure in a range [30 °; 60 °]. Alternatively, other general height structures can be used, for. B. in the form of a circumferential zig-zag pattern.

It is still a further development that the surface structure comprises a roughened surface, for. B. an isotropic or anisotropic scattering surface. This results in the advantage that a light mixture directed with respect to an azimuthal and / or polar angle can be achieved.

Also, the reflection surface or inside of the light-guiding element can be wholly or partially colored monochrome or multicolor, whereby a color of the emitted light can be colored.

The reflective region of the light guide, z. B. the inside, may be designed generally mirroring or diffuse reflective, z. B. by means of a coating or a film. The coating or the film may, for. B. at least one layer of aluminum, silver, a dielectric coating and / or z. B. also have barium sulfate. Also, the reflection surface of the light guide, z. B. the inside, an optical film, z. As a highly reflective mirror film or diffuser film (so-called "Brightness Enhancement Film", BEF), or have such a coating, whereby an efficiency is increased.

In the following figures, the invention will be described schematically with reference to exemplary embodiments. In this case, the same or equivalent elements may be provided with the same reference numerals for clarity.

1 shows in a view obliquely from the front or top of an inventive lighting module without attachment element;

2 shows the light module as a sectional view in an oblique view;

3 shows in an oblique view the light module with an overlying attachment element;

4 shows the light module with the overlying attachment element in an enlarged section in an area of an inner bayonet mount;

5 shows in a view obliquely from the front of a group of light emitting diodes of the lighting module in a further arrangement;

6 shows in a view obliquely from the front a group of LEDs of the lighting module in yet another arrangement;

7a shows a sectional side view of a light emitting diode surrounding light guide with a drawing of a possible light path;

7b shows in a view obliquely from the front of the light-emitting diodes surrounding light-emitting element 7a with the possible light path;

8th shows a sectional side view of the light-emitting diodes surrounding the light-emitting diodes 7a with several possible light paths;

9 shows a sectional side view of a light-emitting element surrounding the light-emitting diodes according to a further embodiment with a plurality of possible light paths;

10 shows a sectional side view of a light-emitting element surrounding the light-emitting diodes according to yet another embodiment with a plurality of possible light paths;

11 shows in a view obliquely from the front, the light guide from the light module 1 ;

12 shows the light guide 11 in plan view; and

13 shows a section of the light guide 12 ,

1 shows in a view obliquely from the front or top of an inventive lighting module 1 without attachment element. 2 shows the light module as a sectional view in an oblique view.

The light module 1 has a substantially disc-shaped circuit board 2 on, which in a central region Z of a front side with a plurality of light sources in the form of light-emitting diodes 3 is equipped. The light-emitting diodes 3 may similarly emit light or differ in their brightness and / or color. An arranged in a cross-shaped matrix pattern light emitting diodes 3 common, substantially hollow cylindrical light-guiding element 4 surrounds the LEDs 3 encircling laterally. A front edge 5 of the light-guiding element 4 limited and surrounds a substantially circular disk-shaped light exit opening L. The light exit opening L corresponds in other words a front opening of the light guide 4 , The through the hollow cylindrical shape straight or parallel inside 4a , which is designed to be reflective, has the advantage that an angular distribution of the light sources 3 radiated light beam is rotationally symmetric.

The circuit board 2 is also in a surrounding region Z surrounding the surrounding area U with further electronic components 30 equipped, z. B. with resistors, capacitors and / or logic devices, eg. B. as part of a driver logic. The other electronic components located in the surrounding area U. 30 are from a ring cover 6 arched, which with a rear edge on the circuit board 2 rests. The ring cover 6 is by means of two screws 7 attached and has a connector bushing 28 for electrical contacting of a likewise on the circuit board 4 attached plug 29 on.

The ring cover 6 has a substantially circular cylindrical inner wall 8th (According to an inner circumferential surface or inner side wall), which the central region Z of the lighting module 1 and thus also the light guide 4 concentrically surrounding laterally. The ring cover 6 also has a substantially circular cylindrical outer wall 9 (corresponding to an outer lateral surface or outer side wall). The outer wall 9 has the same height as the inner wall 8th , The inner wall 8th and the outer wall 9 can with their back edge on the circuit board 2 rest and at its front edge by a top wall 10 be connected. The top wall 10 is here designed as an annular, flat plate. The light guide 4 and the ring cover 6 may be separate components, be interconnected components or be integrated with each other.

In the inner wall 8th the ring cover 6 is a first mounting interface in the form of an internal bayonet mount 11 integrated. In the outer wall 9 the ring cover 6 is a second mounting interface in the form of an outer bayonet mount 12 integrated. Each of the bayonet mountings 11 and 12 has three times each one accessible from the front longitudinal slot 13 , at the end of which is a short transverse slot at right angles 14 attaches. The longitudinal slot 13 has a horizontal bottom, which can also be used as a position adjustment aid. An attachment element may be one to one of the bayonet mountings 11 or 12 have matching bayonet base, which in the longitudinal slot 13 is plugged in and by a rotation in the transverse slot 14 is fastened. For locking the bayonet mount and the bayonet socket, the transverse slot 14 a detent nose over which a corresponding catch (against) nose 15 of the bayonet socket can be pushed.

The light exit opening L and the inner wall 8th and the outer wall 9 close at the same height. This allows the attachment element easy to rest with the ring cover 6 to be brought. The light module 1 In other words, has a substantially planar front side on which the ring cover 6 and the light guide 4 complete flush.

The light module 1 can simply be used in a heat sink (not shown), eg. B. by flat support on its back, z. B. by insertion into a corresponding receptacle of the heat sink. This provides efficient cooling in a simple manner.

3 shows in an oblique view the light module 1 with a hovering optical element as the attachment element in the form of a reflector 16 , 4 shows the light module with the reflector above it 16 in an enlarged section in an area of an inner bayonet mount 11 , The reflector 16 has a pot-like, z. B. parabolic, shaped reflective inside 17 and can with a rear light inlet opening (not shown) on or close to the light exit opening L of the light guide 4 be put on. For attachment to the light module 1 has the reflector 16 a rear bayonet socket 18 for engagement with the inner (smaller) bayonet socket 11 of the light module 1 on. The bayonet socket 18 has three longitudinal slots complementary to the bayonet mount 19 and transverse slots 20 on, being in the transverse slot 20 a catch 15 located. Similarly, another attachment with a correspondingly larger bayonet base and a correspondingly larger light entrance opening on the outer bayonet mount 12 be attached.

5 shows in a view obliquely from the front of a group of light-emitting diodes 3 for use, for. B. in the light module 1 in a further arrangement. The light-emitting diodes 3 are arranged in a rectangular (m × n) matrix pattern (here a 5 × 5 square matrix pattern).

6 shows in one too 5 analog view a group of light-emitting diodes 3 in yet another arrangement. The light-emitting diodes 3 are now arranged in a pattern of concentric rings with a central placement.

There are other patterns possible, for. B. a hexagonal pattern.

7a shows a sectional view in side view of the light-emitting diodes 3 surrounding light guide 4 with a drawing of a possible light path P from one of the light-emitting diodes 3 to the light exit opening L. 7b shows the light guide 4 in a view from diagonally forward. In 7a is next to the light guide 4 nor the ring cover 6 drawn for the right side.

Referring to both figures emits a light emitting diode 3 As a Lambertian radiator typically essentially forward in a front half space, which is also around to the Centered front symmetry axis is centered. Thus, a part of the light-emitting diodes occurs 3 emitted light directly through the light exit opening L, while another part one or more times on the reflective inside 4a , which serves as a reflection surface, is reflected before being output through the light exit port L. The drawn light path P represents one of the central light emitting diode 3 emitted and twice on the inside 4a reflected light beam.

8th shows a sectional view in side view of the light-emitting diodes 3 surrounding light guide 4 with several possible light paths P one of the LEDs 3 , wherein the light paths P are shown as simple lines.

The light of the LEDs 3 is by means of the light guide 4 acting as a "light channel" from the plane of the LEDs 3 to a higher level of the light module 1 guided, namely to the plane of the light exit opening L. This is the for the electronic components 30 required space, which is represented by the surrounding area U or the volume of the ring cover, bridges and defines a new, higher light exit plane.

Attachment elements can then be brought arbitrarily close to the light exit opening L as the new light-emitting plane, whereby Einkoppelverluste be avoided. The light-emitting diodes 3 and the other electronic components 30 can be protected. Electrically conductive attachment elements (for example aluminum reflectors) can, in the case of an electrically non-conductive design of the light-guiding element, be separated from the electrically conductive parts on the printed circuit board 2 be isolated, which makes it easier to comply with air and creepage distances.

The attachment element may be generally configured as an optic or optical element, e.g. As a reflective optic (eg, as a reflector) or as a refractive optic (eg, as a lens or lens). The attachment element may also be an optically substantially non-effective element, for. B. a transparent cover.

9 shows a sectional view in side view of the LEDs 3 surrounding light guide 31 according to a further embodiment with a plurality of possible light paths. A contour of the inside 32 the still substantially hollow cylindrical Lichtleitelements 31 is now frustoconical with a diverging upward or forward course. This gives the advantage that the radiation of the light-emitting diodes 3 emitted light beam can be collimated, resulting in a narrower angular distribution. It has proven to be advantageous that an angle bevel (also called "draft angle") α lies in a range between 1 ° and 10 °, in particular between 1 ° and 5 ° (including the end values).

10 shows a sectional view in side view of the LEDs 3 surrounding further light guide 33 according to yet another embodiment with multiple possible light paths. A contour of the inside 34 the still substantially hollow cylindrical Lichtleitelements 33 is now reversed frusto-conical with a tapered upward or forward course. This gives the advantage that the radiation of the light-emitting diodes 3 emitted light beam can be decollimated, resulting in a broader angular distribution. It has proved to be advantageous that the angle bevel α lies in a range between -1 ° and -10 °, in particular between -1 ° and -5 ° (including the end values).

11 shows in a view obliquely from the front again the light guide 4 , 12 shows the light guide 4 in plan view and 13 shows a section of the light guide 4 out 12 , Referring to the three figures, has light guide 4 on its reflective inside 4a a surface structure in the form of a circumferential (general) wave structure. The wave structure may, for. For example, as shown may include a sinusoidal wave structure, but also a shape based on splines or even a free form. It has proved to be advantageous that a so-called "peak-to-valley" angle β of the wave structure in a range [30 °; 60 °]. Due to the surface structure is a light mixture of the light-emitting diodes 3 emitted light, with respect to a brightness and / or a color.

Alternatively, other surface structures may be used, e.g. B. in the form of a circumferential zig-zag pattern.

Of course, the present invention is not limited to the embodiments shown.

Thus, the reflection surface of the light guide, z. B. the inside, an optical film, z. As a highly reflective mirror film or diffuser film (so-called "Brightness Enhancement Film", BEF), or have such a coating, whereby an efficiency is increased.

Thus, the reflection surface of the light guide may have a roughened surface or be, for. B. an isotropic or anisotropic scattering surface. This results in the advantage that a light mixture directed with respect to an azimuthal and / or polar angle can be achieved.

Also, the reflection surface of the light-guiding element can be wholly or partially colored monochrome or multicolor, whereby a color of the emitted light can be colored.

Features from the different embodiments can be combined, e.g. As a wave pattern on the inside of the light guide with a frusto-conical contour of the inside, etc., as long as this is not explicitly excluded.

LIST OF REFERENCE NUMBERS

1

light module

2

circuit board

3

led

4

light guide

4a

Inside the light guide

5

front edge of the light-guiding element

6

ring cover

7

screw

8th

inner wall

9

outer wall

10

top wall

11

inner bayonet mount

12

outer bayonet mount

13

longitudinal slot

14

transverse slot

15

locking lug

16

reflector

17

inside

18

bayonet base

19

longitudinal slot

20

transverse slot

28

Connector gland

29

plug

30

Electronic Components

31

light guide

32

Inside the light guide

33

light guide

34

Inside the light guide

L

Light opening

U

Environmental area of the circuit board

Z

central area of the circuit board

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007015475 A1 [0003]

Claims (15)

Light module ( 1 ), comprising - a printed circuit board ( 2 ), which at its front side with at least one light source ( 3 ), in particular light-emitting diode, is equipped, and - a hollow light-conducting element ( 4 ; 31 ; 33 ), which the at least one light source ( 3 ) circumferentially surrounds and over the at least one light source ( 3 ) extends forward, - wherein an inside ( 4a ; 32 ; 34 ) of the light guide element ( 4 ; 31 ; 33 ) is configured at least partially reflective and a front opening of the light-guiding element ( 4 ; 31 ; 33 ) a light exit opening (L) of the light module ( 1 ) corresponds. Light module ( 1 ) according to claim 1, wherein a plane of the light exit opening (L) parallel to a plane of the at least one light emitting diode ( 3 ) lies. Light module ( 1 ) according to one of the preceding claims, wherein the light-guiding element ( 4 ; 31 ; 33 ) has a substantially hollow cylindrical basic shape. Light module ( 1 ) according to one of the preceding claims, wherein the light-guiding element ( 4 ) consists of an electrically non-conductive material. Light module ( 1 ) according to one of the preceding claims, comprising at least one receiving means ( 11 . 12 ) for receiving an attachment element ( 16 ) via the light exit opening (L). Light module ( 1 ) according to claim 5, wherein the receiving means as a mounting interface ( 11 . 12 ) is configured. Light module ( 1 ) according to one of the preceding claims, wherein the lighting module ( 1 ) a cover ( 6 ) for at least a part of on the front side of the printed circuit board ( 2 ) arranged electronic components ( 30 ), wherein a front side ( 10 ) of the cover ( 6 ) lies substantially in the plane of the light exit opening (L). Light module ( 1 ) according to one of the preceding claims, wherein the light-guiding element ( 4 ; 31 ; 33 ) laterally at least in sections circumferentially of a ring cover ( 6 ) for at least a part of on the front side of the printed circuit board ( 2 ) arranged electronic components ( 30 ) is surrounded. Light module ( 1 ) according to one of the preceding claims, wherein the light-guiding element ( 4 ; 31 ; 33 ) through the light exit opening (L) direct access to the at least one light source ( 3 ). Light module ( 1 ) according to one of the preceding claims, wherein the light-guiding element ( 31 ) has a front widening inside. Light module ( 1 ) according to one of claims 1 to 9, wherein the light-guiding element ( 33 ) has a forwardly tapered inside. Light module ( 1 ) according to one of the preceding claims, wherein the inside ( 4a ; 32 ; 34 ) of the light guide element ( 4 ) has an optically effective surface structure. Light module ( 1 ) according to claim 12, wherein the surface structure comprises a wave structure. Light module ( 1 ) according to one of claims 12 or 13, wherein the surface structure comprises a roughened surface. Light module ( 1 ) according to one of the preceding claims, wherein the inside of the light-guiding element ( 4 ) is at least partially colored.

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